Such a rotary heat exchanger typically has with a rotatably mounted rotor and forms a first flow sector for the first fluid stream and a second flow sector for the second fluid stream through which the rotor passes during a rotation, a frame in which the rotor is rotatably supported, and a sealing assembly that separates an inflow side of the first fluid stream and an outflow side of the second fluid stream respectively from the outflow side of the first fluid stream and from an inflow side of the second fluid stream.
During operation of such a rotary heat exchanger, the rotor, which is a rotating storage mass, must be sealed relative to the housing and the frame of the rotary heat exchanger. Moreover, the two fluid flows upstream and downstream from the rotary heat exchanger must also be separated from and sealed with respect one another. Leakage during operation of the rotary heat exchanger can be prevented for the most part by these sealing measures.
It is necessary for such leakage to be prevented, since the supply air quality is otherwise reduced, for example, because components of the exhaust air get into the inlet air stream; what is more, leaks occur from the outside air into the outgoing air, for example, where higher-powered fans need to be installed for the outside air and/or inlet air stream, since greater quantities of air must be conveyed than are actually required in order to achieve the desired inlet air volume; disturbances also arise with respect to the recovery performance of the rotary heat exchanger, since bypass flows that flow around the rotor or storage mass reduce the overall performance of the rotary heat exchanger.
On the other hand, certain gaps or spaces are necessary between the rotor forming the heat-storage mass and the housing and/or frame parts that are stationary relative to it, since deviations of the rotor forming the storage mass from the ideal cylinder shape and other construction tolerances would inevitably lead to unwanted friction and result in damage. The gaps and spaces that are therefore necessary must be sealed by the sealing assembly of the rotary heat exchanger.